NaVorro Bowman, Derrick Johnson top NFL's best inside linebackers

In the NFL, defense is changing, and the inside linebacker positions are changing with it. Over the last two seasons, nickel defenses have been the league's base designs, meaning that more than ever, teams are taking at least one of their starting linebackers off the field on first and second downs in favor of another defensive back. This is in response to an increase in three- and four-receiver sets on former running downs, and it forces those linebackers who stay on the field to do more than perhaps they've ever had to before.

In past eras, middle and inside linebackers could hide between the guards and be pure thumpers; the Ray Lewises and Jack Lamberts of the world were the exception, not the rule. These days, if all you can do is stop the run, you'll be a situational player at best. Some pundits have said the traditional inside 'backer is a dying breed, and that's true to a very large degree. The best inside guys must be full-field defenders, and there's no question that the physical dimensions have changed. Now, as it was in the 1970s, you can play middle linebacker at 230 pounds -- the difference is that the players you're playing against have modern heights and weights.

It's a difficult thing to do; to weigh aggressive run-stopping with elite pass coverage, and it's why the best inside men are so valuable. Here are the 10 players we believe do their jobs the best.

Freeman may be the most underrated player on this list -- the undrafted free agent from Mary Hardin-Baylor has built quite the resume in just two seasons as a starter. Last season, he bumped his sack total from 2.0 to 5.5, and doubled his interception total. Freeman is a rangy hitter who's best in short-area coverage, but he can do it all. There may be question marks along certain parts of the Colts' defense, but there are none wherever Freeman lines up.​

Lost in the mess that was Detroit's 2013 season was the fact that the Lions' linebacker corps played at a very high level. DeAndre Levy was an interception machine on the outside, and Tulloch -- who ranked second behind only NaVorro Bowman in Pro Football Focus's positional rankings -- had his best season to date.

"When you have guys together for a long period of time you can build a chemistry with each other," Tulloch told the team's official site last November. "I think me and Levy have really had a chance to learn the ins and outs of each other; where the other is going to be on a certain play or call, and how to help each other out. We’ve gained that bond with each other and have been able to trust each other."

So, there could be more greatness from Detroit's linebackers, and it will start with Tulloch.

Alonso will also miss the entire 2014 season with a torn left ACL, but like Dallas' Sean Lee, his omission from this list would have been absolutely wrong, because he was so utterly dominant in his rookie campaign of 2013. Taken in the second round out of Oregon, Alonso became a one-man wrecking crew from Day One, amassing two sacks, four interceptions and 159 total tackles. There wasn't a tight end in the league Alonso couldn't match up with, nor a running back he couldn't deal with in space. This is a brutal hit for a Buffalo defense that couldn't afford his absence, but we're sure Alonso will be one to watch in 2015 and beyond.​

If Lee could simply stay healthy, he might be at the top of our list, so transformative is his effect on Dallas' defense when he's in there. But Lee has missed 15 games in the last two years and has never played 16 games in a full season. In just 11 games last season, he picked off four passes for a league-leading 174 yards and a touchdown. Perhaps no linebacker in the NFL is quicker and more decisive to a specific zone or receiver than Lee; when he's on point, he makes life miserable for opponents. Unfortunately, Lee will miss the entire 2014 season with a torn left ACL. It's a sign of his greatness that he's still on this list, but with his fifth season a wash before it even begins, one wonders if this is the beginning of the end for this rare and special player.​

The secondary gets most of the attention when people talk about the Seattle defense, but that secondary wouldn't be as tough to deal with, and the Seahawks' defensive line wouldn't be as stout, without Wagner's efforts. It's hard to believe he's only got two NFL seasons under his belt; like Luke Kuechly, Wagner hit the ground running from an awareness standpoint and he's never stopped. Wagner can hit backs in the middle, run out for pass coverage and make the calls that keep Seattle's front seven among the best and most quickly reactive in the league, and as he did at Utah State, he can do it when he's the only player at linebacker depth. ​

Though NaVorro Bowman has taken the role of best inside linebacker in the league away from Willis (there's a spoiler for you), it's just as impressive how Willis has been able to stave off the ravages of time. He's had more than 100 total tackles in all but one of his seven NFL seasons, and among those linebackers who are truly every-down players, few if any play the run better. He's on a Hall of Fame track, and by no means is his best work behind him. Willis will be tested early in the 2014 season, when Bowman misses a number of weeks as he recovers from knee surgery.​

Since the first day he hit an NFL field in 2012, Kuechly has been a special player -- like Sam Mills, Zach Thomas and Lofa Tatupu before him, the Panthers' first-round pick two years ago has understood the pro game at a very rare level for his age. He's won the Defensive Rookie of the Year and the AP Defensive Player of the Year so far, and the sky's the limit. Kuechly doubled his sack and interception totals in 2013, and his ability to play against the run -- a bugaboo when he came out of Boston College -- is steadily improving. If he's No. 1 on this list within the next three years, don't be surprised.

The Cardinals are really going to regret letting Dansby go, especially following Daryl Washington's year-long (at least) suspension for his latest violation of the league's drug policies. Last year, the Cardinals ranked second in overall defense in Football Outsiders' opponent-adjusted metrics, and the duo of Dansby and Washington was a huge part of that. For the Cleveland defense, defined as it will be by new head coach Mike Pettine, Dansby will play a similar role to the one he did in Arizona -- he'll cover from the middle to the numbers, and use his outstanding play recognition skills to snuff out opposing run games. The thought was that Dansby will see diminishing returns at age 32, but the Browns disagreed with a new four-year contract, and they're probably right.

If you want to see Johnson's true positional value, go back to Kansas City's loss to the Colts in the wild-card round of the 2013 playoffs. As he often did last season, Chiefs defensive coordinator Bob Sutton used a dime-base defense -- over and over, six defensive backs on the field and one linebacker. Johnson was that linebacker, and in dime situations, linebackers are tasked to do a multitude of things -- make calls, adjust to audibles (especially in no-huddle situations) and play pass and run equally. The Chiefs blew a 38-10 third quarter lead, but that wasn't on Johnson, who's been one of the more underrated players at his position for a number of years. No inside linebacker received a higher coverage grade from PFF than Johnson last year, and he matched his career high with 4.5 sacks. If you want to put one 'backer on the field for a high percentage of plays, there's nobody better. Johnson was the engine that made Sutton's aggressive defense work. ​

​​Bowman could miss as much as half the 2014 season with the knee injury he suffered in the NFC Championship Game, but that doesn't take a thing away from the fantastic season he enjoyed in 2013, or his potential when he returns. He'd been a worthy first-team All-Pro in each of the last three seasons, but he turned it up more than a notch for San Francisco last year. He was Pro Football Focus' top-ranked inside linebacker by a fairly wide margin, and he ranked in the top three of most of Football Outsiders' charting stats for the position. Like battery mate Patrick Willis, Bowman possesses the toughest combo to have at this position -- the ability to rock running backs into next week with his downhill hits, and to deal with tight ends and slot receivers in coverage. Moreover, his field awareness has improved exponentially since the 49ers took him in the third round out of Penn State in 2010. When discussing the best inside 'backers, the line starts here, and for good reason.​

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